Method of forming concrete structures with treated form panels



Sept. 23, 1969 F. L. WILLIAMS METHOD OF FORMING CONCRETE STRUCTURES WITHTREATED FORM PANELS Filed Jan. 21, 1965 m z fn/ra/P FRANK 4. no; 4444455y d 2M4 Arr P/VZYS United States Patent 3,468,988 METHOD OF FORMINGCONCRETE STRUCTURES WITH TREATED FORM PANELS Frank L. Williams, DesMoines, Iowa, assignor, by mesne assignments, to International ConcreteSystems Company, Bala Cynwyd, Pa., a corporation of Delaware Filed Jan.21, 1965, Ser. No. 426,885 Int. Cl. B28b 1/14, 7/36; 1304b 1/16 11.5.Cl. 264-31 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates toa concrete wall construction panel and more particularly to a concretewall construction panel having a film thereon which prevents the panelfrom sticking to concrete.

The use of concrete wall construction panels which are constructed ofaluminum or aluminum alloys has become widespread in recent years. Onedisadvantage in aluminum construction panels is the tendency of them tostick to the concrete. This makes it rather difiicult to remove thepanels from the hardenend concrete. Certain types of the aluminumconstruction panels cause a simulated brick effect to be formed in thefinished concrete wall. The sticking of the construction panels to thesesurfaces result in the panels pulling olf fragments of the hardenedconcrete when they are removed therefrom. This results in a somewhatless than desirable decorative surface on the concrete wall due to theholes, etc. caused by the fragments being pulled from the concrete.

Additionally, it has been found that the aluminum hydroxides in theconcrete have a tendency to react with the aluminum forms therebycreating a serious problem for the builder.

Building contractors have attempted to prevent the construction panelsfrom sticking to the concrete by oiling the interior faces of theconstruction panels. The use of oil on the construction panels has onlybeen partially successful.

Therefore, it is a principal object of this invention to provide aconcrete Wall panel which has a film thereon to prevent it from stickingto the concrete.

A further object of this invention is to provide a concrete wallconstruction panel which will not react with the aluminum hydroxides inthe concrete.

A further object of this invention is to provide a concrete wallconstruction panel which has a film formed integrally thereon whichprevents the panel from sticking to concrete.

A further object of this invention is to provide a concrete wallconstruction panel which may be removed from a concrete wall withoutremoving fragments of the wall.

A further object of this invention is to provide a concrete wallconstruction panel having a film thereon which does not come off thepanel.

A further object of this invention is to provide a concrete wallconstruction panel having a film thereon which is formed by the reactionof the construction panel and the substance applied thereon.

It is a further object of this invention to provide a concrete wallconstruction panel which is economical of manufacture, durable in useand refined in appearance.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, andcombination of the various parts of the device, whereby the objectscontemplated are attained as hereinafter more fully set forth,specifically pointed out in the claims, and illustrated in theaccompanying drawings, in which:

FIG. 1 is a perspective view of the concrete wall construction panel;

FIG. 2 is a sectional view of the wall construction panel as seen online 22 of FIG. 1 at an enlarged scale, and

FIG. 3 is a side sectional view illustrating the manner in which theconcrete wall construction panels are utilized to form a concrete wall.

The numeral 10 generally designates the construction panel having aninterior face 11 and exterior face 13 and edge flanges 15. As seen inFIG. 2, the numeral 17 represents a film which has been applied to theinterior surface 11 of panel 10 to prevent the panel from sticking tothe concrete which is generally indicated at 19 in FIG. 3.

Film 17 is formed on panel 10 by either of the following examples:

Example No. 1.A quantity of caustic soda and a quantity of water arefirst heated. The heated caustic soda-water solution is then applied topanel 10 by any convenient method such as by dipping panel 10 into theheated solution or by spraying the solution onto panel 10. .It is onlynecessary to treat the inner surface of panels 10 as it is only theinner surface thereof which comes into contact with the concrete. Panel10 is then allowed to dry. A soot colored film is formed on panel 10 dueto the reaction of the aluminum and/or aluminum alloys in panel 10 withthe caustic soda and water. This reaction causes film 17 to be bonded onpanel 10 which prevents film 17 from being rubbed or washed therefrom.

While film 17 has never been chemically analyzed, it is believed that itis comprised of aluminum hydroxide or aluminum oxide. The resultantcomposition of film 17 would necessarily vary depending on thecomposition of panel 10.

It has been discovered that the most ideal proportion of caustic soda towater is approximately 5-10% by weight. While other proportions workwith varying degrees of success, the foregoing range is the mostdesirable. It has also been found that the best results are obtainedwhen the caustic soda-water solution is heated to l60 degreesFahrenheit. Varying degrees of success are obtained in forming film 17by varying the'solution temperature but the foregoing range has beenfound to be the most desirable.

Example No. 2.A quantity of muriatic acid is applied to panel 10 by anyconvenient means such as described in Example No. 1. The muriatic acidreacts with the aluminum and/or aluminum alloys in panel 10 to form sootcolored film thereon. The soot colored film of Example No. 2 is notquite as black as the soot colored film of Example No. 1. The reactionbetween panel 10 and the muriatic acid causes film 17 to be formed andto be bonded to panel 10 which aids in preventing film 17 from beingrubbed or washed off panel 10. While the film 17 obtained in Example No.2 has never been chemically analyzed, it is believed that film 17 iscomposed of aluminum chloride. The resultant composition of film 17would necessarily vary depending on the compositon of panel 10.

The normal method of operation is as follows: A plurality of panels 10,which have film 17 thereon, are assembled to provide a wall constructionform such as seen in FIG. 3. Panels 10 have alsobeen coated with a layeror film of oil to further aid in removing the panels from the hardenendconcrete. The concrete is poured into the form and permitted to hardenin conventional fashion. When the concrete has hardenend, panels 10 arestripped or removed therefrom. Film 17 prevents panel 10 from reactingwith the aluminum hydroxide and the concrete. Film 17 also preventspanel 10 from sticking to the concrete and insures that panel 10 may beremoved from the hardened concrete without destroying the desireddecorative efiect thereon.

Thus from the foregoing it can be seen that the device accomplishes atleast all of its stated objectives.

I claim:

1. A method for forming a concrete structure in an assembly of aluminumpanels having inner aluminum surfaces defining a construction formcomprising the steps of applying a sodium hydroxide solution to theinner surfaces of the panels, subsequently applying an oil substance tothe surface treated with the sodium hydroxide solution, pouring concreteinto the construction form defined by the inner surfaces, allowing theconcrete to harden into a formed structure, and stripping the panelsfrom the formed structure.

2. Method in accordance with claim 1 wherein sodium hydroxide is from 5%to 10% by weight of said solution.

3. Method in accordance, with claim 1 wherein the solution applied tothe inner surfaces of the panels is at a temperature of approximately150 to 160 F.

References Cited UNITED STATES PATENTS 1,575,122 3/1926 Madsen 117 5.s2,669,752 2/1954 Pratt 2 4 337 x 2,806,277 9/1957 Hand et al. 264-343,217,356 11/1965 Stursman -264--69 x FOREIGN PATENTS 223,994 11/ 1924Great Britain. 766,858 1/1957 Great Britain.

ROBERT F. WHITE, Primary Examiner K. J. HOVET, Assistant Examiner US.Cl. X.R.

